JP2003294685A - Gas sensor, gas sensor mounting structure and method for mounting gas sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas sensor which is hard to lower a clamping force of a screw even when the sensor is installed and used under a high temperature condition capable of exposing when the sensor is mounted, for example, at a vehicle under a high temperature condition, and which is further hard to drop from piping or the like mounted even when a vibration is applied. <P>SOLUTION: The gas sensor 10 comprises a sensor element 1 having a predetermined function, and a housing 5 containing the element 1 therein and having a predetermined threaded part 2 and a sealing surface 4 for forming a seal 3 with a part to be mounted forward of an entering direction of the element 1 from the threaded part 2. In this sensor, a loosening torque at 850°C (1,123 K) when the housing 5 is screwed to the part to be mounted is 9 N m or more, and is calculated according to a predetermined formula. A predicted value X<SB>1</SB>of a gap formed between the surface 4 and the part to be mounted at 850°C (1,123 K) calculated according to a predetermined formula is 31 μm or less. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas sensor, a gas sensor mounting structure, and a gas sensor mounting method, and more specifically, it is used under high temperature conditions, for example, high temperature conditions that may be exposed when mounted on a vehicle or the like. The present invention relates to a gas sensor that does not easily fall off from a mounted portion, a gas sensor mounting structure that mounts the gas sensor, and a gas sensor mounting method.

[0002]

The exhaust pipe of an automobile (pipe), a predetermined gas component in the exhaust gas (e.g., NO _X) in order to detect the various gas sensor is attached. This type of gas sensor is generally attached to a predetermined pipe 6 as shown in FIG.

That is, the gas sensor 10 is, for example, NO _X.
The sensor element 1 having a function of detecting the pressure sensor 1 and the sensor element 1 are housed in the sensor element 1, and the seal portion 3 is provided by contacting the screw element 2 and a predetermined portion of the attached portion (boss 7) on the outside thereof. And a housing 5 having a sealing surface 4 capable of forming In addition, a boss 7 having a thread groove that can be screwed into the threaded portion 2 of the housing 5 is fixed to the pipe 6 to which the gas sensor 10 is attached. 10 is attached to the pipe 6. When the gas sensor 10 is attached, as shown in FIG.
In some cases, the gasket 8 is arranged on the seal surface 4 to form the seal portion 3.

Further, as shown in FIG. 3, the housing 5
A rotating member (rotary hexagon 15) that can rotate concentrically with the central axis of the housing 5 is arranged outside the housing 5 without rotating itself, and the sealing surface 4 is pressed against the boss 7 by screwing the rotating member. In some cases, 10 may be attached. Further, as in the case shown in FIG. 2, even if the rotary hexagon 15 is used, the gasket 8 may be arranged on the seal surface 4 to form the seal portion 3 (FIG. 4).

[0005]

However, even if the housing is screwed by an appropriate tightening torque and the gas sensor is attached to the attached portion, the temperature of the pipe itself becomes high and the place where the gas sensor is attached is exposed to high temperature. May be done. For example, when a gas sensor is attached to an exhaust pipe of an automobile and used, the gas sensor is attached at 80
It will be exposed to a high temperature of 0 to 900 ° C. At this time,
Depending on the combination of the material forming the boss and the material forming the housing or gasket,
A gap is likely to be formed in the seal portion due to the magnitude relationship of the thermal expansion coefficients of these materials.

When the above-mentioned gap is formed in the seal portion, the tightening force of the screw gradually decreases as the gap increases. As described above, if the gas sensor is continuously used while the tightening force of the screw is reduced, the gas sensor may drop from the pipe. Especially when using a gas sensor in an installation environment where vibration is applied continuously or intermittently, the possibility of the gas sensor falling off increases,
There is a need for measures to eliminate such problems.

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a high temperature condition, for example, a high temperature condition that can be exposed when mounted on a vehicle or the like. The gas sensor is such that the tightening force of the screw does not easily decrease even when it is installed and used, and it is difficult for it to fall off from the attached pipes even when vibration is applied, and the gas sensor mounting structure with this gas sensor attached. , And a gas sensor mounting method.

[0008]

That is, according to the present invention, a sensor element having a function of detecting a predetermined gas component, and a predetermined sensor element formed inside the sensor element and outside the sensor element. A gas sensor, comprising: a threaded portion to be screwed to the mounted portion; and a housing having a sealing surface that forms a seal portion with the mounted portion in front of the threaded portion in the direction in which the sensor element enters. And the loosening torque at 850 ° C. (1123K) when the housing is screwed to the attached portion is 9N.
・ The expected value X _{1 of the} gap formed between the sealing surface and the mounted portion at 850 ° C. (1123 K) is 31 μ, which is calculated to be m or more and is calculated according to the following equation (13).
There is provided a gas sensor having a thickness of m or less.

[0009]

X ₁ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (13) (where X ₁ is the expected value of the gap (μm), L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)).

In the present invention, the sealing surface is provided with a gasket, and the expected value X _{2 of the} gap is expressed by the following formula (1
It is preferably calculated according to 4). In the present invention, the material forming the gasket is SUS430, SU
S304, SUS310, SUS316, and SUS3
It is preferably at least one selected from the group consisting of 21.

[0011]

X ₂ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ ) − (L ₃ × α ₃ )} × 1123 (14) (where X ₂ is a gap prediction Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (× 1
0 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10 ^-6
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. )

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed therein, and the attached portion is provided in front of the approach direction of the sensor element. A housing having a sealing surface that forms a sealing portion, and a rotating member that has a screw portion that is screwed to a predetermined mounted portion formed on the outside thereof and that is rotatable concentrically with the central axis of the housing. 850 ° C. (11) when the gas sensor is attached to the attached portion by screwing the rotating member to the attached portion.
23K), the loosening torque of the rotating member is 9 N · m
In addition to the above, the expected value X _{3 of the} gap formed between the seal surface and the mounted portion at 850 ° C. (1123K) calculated according to the following formula (15) is 31 μm or less. A gas sensor is provided.

[0013]

[Equation 15] X ₃ (μm) = {(L ₁ × α ₁ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (15) (However, X ₃ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. to bottom length (μm), α ₁ is the thermal expansion coefficient of the attachment portion ^{(× 10 - 6 / ℃)} , α 4 are the thermal expansion coefficient of the rotating member ^{(× 10 -6 / ℃),} α 5 housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of

In the present invention, a gasket is provided on the sealing surface, and the predicted value X _{4 of the} gap is expressed by the following formula (1
It is preferably calculated according to 6).

[0015]

X ₄ (μm) = {(L ₁ × α ₁ ) − (L ₃ × α ₃ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (16) ( Where X ₄ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the thickness of the gasket (μm), L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion of the mounted part (× 10 ⁻⁶⁾
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. )

In the present invention, the material forming the gasket is SUS430, SUS304, SUS310,
It is preferably at least one selected from the group consisting of SUS316 and SUS321. In the present invention, the material forming the rotating member is SUS430, SU.
S304, SUS310, SUS316, and SUS3
It is preferable that it is at least one selected from the group consisting of 21, and the material forming the housing is SUS43.
It is preferably at least one selected from the group consisting of 0, SUS304, SUS310, SUS316, and SUS321.

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed therein, and is screwed to a predetermined mounted portion formed outside thereof. And a housing having a seal surface forming a seal portion in front of the threaded portion in the entrance direction of the sensor element with respect to the threaded portion. A gas sensor mounting structure mounted by screwing a housing at 850 ° C (1123K)
The loosening torque of the housing at 9 N · m or more is calculated according to the following equation (17), 8
Provided is a gas sensor mounting structure, wherein an expected value X _{5 of} a gap formed between the sealing surface and the mounted portion at 50 ° C. (1123K) is 31 μm or less.

[0018]

X ₅ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (17) (where X ₅ is the expected value of the gap (μm), L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)).

In the present invention, it is preferable that the seal portion is formed through a gasket and the predicted value X _{6 of the} gap is calculated according to the following equation (18). In the present invention, the material forming the gasket is S
US430, SUS304, SUS310, SUS31
6 and at least one selected from the group consisting of SUS321.

[0020]

[Equation 18] X ₆ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ ) − (L ₃ × α ₃ )} × 1123 (18) (However, X ₆ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (× 1
0 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10 ^-6
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. )

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed therein, and the attached portion is provided in front of the sensor element in the entering direction. A housing having a sealing surface that forms a sealing portion, and a rotating member that has a screw portion that is screwed to a predetermined mounted portion formed on the outside thereof and that is rotatable concentrically with the central axis of the housing. Is a gas sensor mounting structure mounted on the mounted portion by screwing the rotating member, wherein the loosening torque of the rotating member at 850 ° C. (1123K) is 9 N · m or more. And 850 ° C. calculated according to the following equation (19)
A gas sensor mounting structure is provided, wherein the expected value X _{7 of the} gap formed between the sealing surface and the mounted portion at (1123K) is 31 μm or less.

[0022]

X ₇ (μm) = {(L ₁ × α ₁ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (19) (However, X ₇ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. to bottom length (μm), α ₁ is the thermal expansion coefficient of the attachment portion ^{(× 10 - 6 / ℃)} , α 4 are the thermal expansion coefficient of the rotating member ^{(× 10 -6 / ℃),} α 5 housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of

In the present invention, it is preferable that the seal portion is formed via a gasket and the predicted value X _{8 of the} gap is calculated according to the following equation (20).

[0024]

X ₈ (μm) = {(L ₁ × α ₁ )-(L ₃ × α ₃ )-(L ₄ × α ₄ )-(L ₅ × α ₅ )} × 1123 (20) ( Where X ₈ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the thickness of the gasket (μm), and L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion of the mounted part (× 10 ⁻⁶⁾
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. )

In the present invention, the material forming the gasket is SUS430, SUS304, SUS310,
It is preferably at least one selected from the group consisting of SUS316 and SUS321. In the present invention, the material forming the rotating member is SUS430, SU.
S304, SUS310, SUS316, and SUS3
It is preferable that it is at least one selected from the group consisting of 21, and the material forming the housing is SUS43.
It is preferably at least one selected from the group consisting of 0, SUS304, SUS310, SUS316, and SUS321.

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed inside, and is screwed to a predetermined attached portion formed outside thereof. Screwing the housing with a gas sensor having a threaded portion and a housing having a sealing surface that forms a sealing portion with the attached portion in front of the threaded portion in the entering direction of the sensor element. According to the method of mounting a gas sensor mounted on the mounted portion according to, the loosening torque at 850 ° C. (1123K) is 9 N · m or more, and the following formula (2)
The housing is screwed so that the expected value X _{9 of the} gap formed between the sealing surface and the attached portion at 850 ° C. (1123K) calculated according to 1) is 31 μm or less. A method of mounting a gas sensor is provided.

[0027]

X ₉ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (21) (where X ₉ is the expected value of the gap (μm), L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)).

In the present invention, it is preferable to form the seal portion via the gasket and screw the housing so that the expected value X _{10 of the} gap calculated according to the following formula (22) is 31 μm or less.

[0029]

X ₁₀ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ ) − (L ₃ × α ₃ )} × 1123 (22) (However, X ₁₀ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (×
10 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10
^-6 / ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. )

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed therein, and the attached portion is provided in front of the approach direction of the sensor element. A housing having a sealing surface that forms a sealing portion, and a rotating member that has a screw portion for screwing to a predetermined attached portion formed outside thereof and that is rotatable concentrically with the central axis of the housing. A gas sensor mounting method for mounting the equipped gas sensor to the mounted portion by screwing the rotating member, wherein the loosening torque at 850 ° C. (1123K) is 9 N · m or more, and the following formula ( 23) Expected value X of the gap formed between the sealing surface and the attached portion at 850 ° C. (1123K) calculated according to 23).
There is provided a gas sensor mounting method, characterized in that the rotating member is screwed so that ₁₁ is 31 μm or less.

[0031]

X ₁₁ (μm) = {(L ₁ × α ₁ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (23) (However, X ₁₁ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. Length to the lower end (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ^-6 / ° C), α ₄ is the thermal expansion coefficient of the rotating member (× 10 ^-6 / ° C), α ₅ is the housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of

In the present invention, it is preferable to form the seal portion via the gasket and screw the housing so that the expected value X _{8 of the} gap calculated according to the following formula (24) is 31 μm or less. .

[0033]

X ₁₂ (μm) = {(L ₁ × α ₁ ) − (L ₃ × α ₃ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (24) ( Where X ₁₂ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the gasket thickness (μm), and L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion (× 10
^-6 / ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. )

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to the following embodiments. It should be understood that design changes, improvements, etc. can be appropriately made based on the knowledge of.

According to the present invention, there is provided a sensor element having a function of detecting a predetermined gas component, the sensor element housed in the sensor element, and screwed to a predetermined attachment portion formed outside the sensor element. A gas sensor comprising: a threaded portion; and a housing having a mounting surface and a sealing surface that forms a sealing portion in front of the threaded portion in the direction in which the sensor element enters, the housing being screwed to the mounting portion. In this case, the loosening torque at 850 ° C. (1123K) is 9 N · m or more, and it is formed between the seal surface and the mounted portion at 850 ° C. (1123K) calculated according to the following equation (25). It is characterized in that the expected value X _{1 of the} gap is 31 μm or less.

[0036]

X ₁ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (25) (where X ₁ is the expected value of the gap (μm), L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)).

The embodiment of the present invention will be specifically described by taking the gas sensor mounting structure shown in FIG. 1 as an example.
As described above, FIG. 1 shows a state in which the gas sensor 10 is attached to the pipe 6 by screwing the housing 5 into the boss 7. Here, if the magnitude relationship between the thermal expansion coefficient of the boss 7 is the installation section (alpha ₁₎ and the thermal expansion coefficient of the housing 5 (alpha ₂₎ is α _1> α _2, pipe 6 is hot in this state In the gas sensor of this embodiment, the thermal expansion coefficient (α ₁ ) of the mounted portion and the sealing surface are reduced, although a gap is formed in the seal portion 3 and the tightening force of the screw is reduced. In relation to the length (L ₁ ) from the mounting portion to the upper end of the mounted portion, 850 ° C. (112 ° C.) when the housing 5 is screwed to the mounted portion (boss 7).
Since the value of the loosening torque at 3K) and the expected value X _{1 of the} gap calculated according to the above equation (25) are predetermined values, the tightening force of the threaded portion 2 is appropriately maintained. Therefore, the gas sensor of the present embodiment is extremely unlikely to fall off from the attached portion (boss 7) even when used in an installation environment where vibration is continuously or intermittently applied under high temperature conditions. Shows the effect.

The “loosening torque” referred to in the present invention is a torque required to remove the fastening object (gas sensor) from the attached portion, or to lose the fastening force between the fastening object and the attached portion. Torque means a measured value actually measured by a torque gauge.

From the viewpoint of further reducing the possibility of falling off, the loosening torque at 850 ° C. (1123K) when the housing is screwed to the mounted portion is 15 N · m or more, and The predicted value X _{1 of the} gap calculated according to (25) is preferably 20 μm or less. From the same viewpoint, 850 ° C (11
It is more preferable that the loosening torque at 23 K) is 20 N · m or more, and the expected value X _{1 of the} gap calculated according to the equation (25) is 15 μm or less.

In the present invention, the upper limit value of the loosening torque is not limited, but from the viewpoint of preventing deformation of the screw part, biting of the screw, etc., it may be equal to or less than the torque at the time of tightening. Further, the lower limit value of the predicted value X ₁ of the gap in the present invention is not limited, and the predicted value X _{1 of the} gap may be a negative value because it is a theoretical value, but it is generally -10 μm or more. Good.

The gas sensor of the present invention can also be configured to have a gasket 8 on the sealing surface 4, as shown in FIG. In this case, the expected value X _{2 of the} gap can be calculated according to the following formula (26).

[0042]

X ₂ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ ) − (L ₃ × α ₃ )} × 1123 (26) (However, X ₂ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (× 1
0 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10 ^-6
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. )

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed in the sensor element, and the attached portion and the seal portion are formed in front of the entering direction. A gas sensor having a housing having a sealing surface, and a rotating member that has a screw portion to be screwed to a predetermined attached portion formed on the outside thereof and that is rotatable concentrically with the central axis of the housing. The loosening torque of the rotating member at 850 ° C. (1123K) is 9 N · m or more when the gas sensor is attached to the attached portion by screwing the rotating member to the attached portion. The predicted value X _{3 of the} gap formed between the seal surface and the mounted portion at 850 ° C. (1123 K) calculated according to the following equation (27) is 31.
There is provided a gas sensor having a thickness of μm or less. Hereinafter, the gas sensor mounting structure shown in FIG. 3 will be described as an example.

[0044]

X ₃ (μm) = {(L ₁ × α ₁ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (27) (However, X ₃ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. to bottom length (μm), α ₁ is the thermal expansion coefficient of the attachment portion ^{(× 10 - 6 / ℃)} , α 4 are the thermal expansion coefficient of the rotating member ^{(× 10 -6 / ℃),} α 5 housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of

As described above, in FIG.
Outside the housing 5 without rotating the gear 5 itself
In addition, the rotating member (rotary
The kissagon 15) is arranged and it is screwed in.
The sealing surface 4 is pressed against the boss 7, and the gas sensor 1
The state where 0 is attached is shown. In addition, to be mounted
Coefficient of thermal expansion of the boss 7 (α)₁) And housing 5 and
And the thermal expansion coefficient of the rotating member (rotary hexagon 15) (α
_Four, Α_Five) Is greater than α₁> Α_Four, Α ₁> Α_FiveWhere is
In this case, assume that the pipe 6 becomes hot in this state.
And a gap is formed in the seal part 3 and the screw part is tightened.
Although the attachment force decreases, the gas sensor of the present embodiment
Thermal expansion coefficient (α₁), And mounted from the sealing surface
Length to the top of the part (L₁) In relation to
Rotating hexagon 1 which is a rotating member on the mounting part (boss 7)
Loosening at 850 ° C (1123K) when screwing 5
Between the torque value and the value calculated according to the above equation (27)
Expected value of the gap X₃Since and are the specified values, tighten the screw
The attachment force is maintained moderately. Therefore, the gas sensor of the present invention
Is a device that is subject to continuous or intermittent vibration under high temperature conditions.
Attached parts even when used in an environment
The effect that it is extremely unlikely to fall out of (boss 7)
Indicates.

From the viewpoint of further reducing the possibility of falling off, the loosening torque at 850 ° C. (1123 K) when the rotating member is screwed to the attached portion is 1
It is preferable that the expected value X _{3 of the} gap calculated according to the equation (27) is 20 μm or less, in addition to 5 N · m or more. Also, from the same viewpoint, 850 ° C. (112
It is further preferable that the loosening torque at 3K) is 20 N · m or more, and the expected value X _{3 of the} gap calculated according to the above equation (27) is 15 μm or less.

In the present invention, the above-mentioned upper limit value of the loosening torque is not limited, but from the viewpoint of preventing the deformation of the screw portion, the biting of the screw, etc., it may be equal to or less than the torque at the time of tightening. Further, the lower limit value of the predicted value X ₁ of the gap in the present invention is not limited, and the predicted value X _{1 of the} gap may be a negative value because it is a theoretical value, but it is generally -10 μm or more. Good.

In the present invention, as shown in FIG. 4, the sealing surface 4 may be provided with a gasket 8. In this case, the expected value X _{4 of the} gap is expressed by the following formula (2
It can be calculated according to 8).

[0049]

X ₄ (μm) = {(L ₁ × α ₁ ) − (L ₃ × α ₃ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (28) ( Where X ₄ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the thickness of the gasket (μm), L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion of the mounted part (× 10 ⁻⁶⁾
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. )

In the present invention, the material forming the gasket is SUS430, SUS304, SUS310,
It is preferably at least one selected from the group consisting of SUS316 and SUS321. These materials are preferable because they are materials capable of exhibiting good sealability in the seal portion and also have good workability.

Further, in the present invention, as the material forming the rotating member and the housing, general-purpose materials are preferably used. As a specific example, the material forming the rotating member is SUS430, SUS304, SUS31.
0, SUS316, and SUS321, and at least one selected from the group consisting of SUS430, SUS304, and SUS3.
At least one selected from the group consisting of 10, SUS316, and SUS321 is preferably adopted.

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed in the sensor element, and is screwed to a predetermined attached portion formed outside the sensor element. A gas sensor having a threaded portion to be mounted and a housing having a mounting surface and a sealing surface that forms a sealing portion in front of the threaded portion in the direction of entry of the sensor element, and the housing is screwed to the mounting portion. It is a gas sensor mounting structure that is mounted by means of the following formula (2) and the loosening torque of the housing at 850 ° C. (1123K) is 9 N · m or more.
9) Expected value of the gap formed between the seal surface and the mounted part at 850 ° C (1123K) calculated according to 9) X ₅
Is 31 μm or less. A gas sensor mounting structure is provided. Hereinafter, the gas sensor mounting structure shown in FIG. 1 will be described as an example.

[0053]

X ₅ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (29) (where X ₅ is the expected gap value (μm) and L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)).

As described above, assuming that the temperature of the pipe 6 becomes high, a gap is formed in the seal portion 3,
Although the tightening force of the screw part 3 is reduced, the gas sensor mounting structure of the present embodiment has a loosening torque value at 850 ° C. (1123 K) and an expected gap value X ₅ calculated according to the above equation (29). Is a predetermined value, the thread 3
The tightening force of is maintained moderately. Therefore, even if the gas sensor mounting structure of the present embodiment is used under a high temperature condition in an installation environment in which vibration is continuously or intermittently applied, the gas sensor 10 is mounted on the mounting portion (boss 7). It has the effect of being extremely unlikely to drop out.

From the viewpoint of further reducing the possibility of falling off, the loosening torque of the housing at 850 ° C. (1123K) is 15 N · m or more, and the predicted gap calculated according to the above equation (29). Value X
₅ is preferably 20 μm or less. From the same viewpoint, it is more preferable that the loosening torque at 850 ° C. (1123K) is 20 N · m or more, and the predicted value X _{5 of the} gap calculated according to the above formula (29) is 15 μm or less.

In the present invention, the upper limit of the loosening torque is not limited, but from the viewpoint of preventing the deformation of the screw portion, the biting of the screw, etc., it may be equal to or less than the torque at the time of tightening. Further, the lower limit value of the predicted value X ₁ of the gap in the present invention is not limited, and the predicted value X _{1 of the} gap may be a negative value because it is a theoretical value, but it is generally -10 μm or more. Good.

The gas sensor mounting structure of the present invention may have a structure in which the seal portion 3 is formed via a gasket 8 as shown in FIG. In this case, the expected value X _{5 of the} gap can be calculated according to the following formula (30).

[0058]

X ₆ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ ) − (L ₃ × α ₃ )} × 1123 (30) (However, X ₆ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (× 1
0 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10 ^-6
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. )

In the present invention, the material forming the gasket is SUS430, SUS304, SUS310,
It is preferably at least one selected from the group consisting of SUS316 and SUS321. These materials are preferable because they are materials capable of exhibiting good sealability in the seal portion and also have good workability.

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed in the sensor element, and the attached portion and the seal portion are formed in front of the entering direction. A gas sensor having a housing having a sealing surface, and a rotating member that has a screw portion to be screwed to a predetermined attached portion formed on the outside thereof and that is rotatable concentrically with the central axis of the housing. , A gas sensor mounting structure mounted on a mounting portion by screwing a rotating member,
The loosening torque of the rotating member at 0 ° C (1123K) is 9
The predicted value X _{7 of the} gap formed between the sealing surface and the mounted portion at 850 ° C. (1123K) is 31 which is not less than N · m and which is calculated according to the following formula (31).
Provided is a gas sensor mounting structure characterized by having a thickness of not more than μm. Hereinafter, the gas sensor mounting structure shown in FIG. 3 will be described as an example.

[0061]

X ₇ (μm) = {(L ₁ × α ₁ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (31) (However, X ₇ is a gap prediction. Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. to bottom length (μm), α ₁ is the thermal expansion coefficient of the attachment portion ^{(× 10 - 6 / ℃)} , α 4 are the thermal expansion coefficient of the rotating member ^{(× 10 -6 / ℃),} α 5 housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of

In FIG. 3, a rotating member (rotary hexagon 15) that can rotate outside the housing 5 concentrically with the central axis of the housing 5 without rotating the housing 5 itself.
Are arranged and screwed into the sealing surface 4
Is pressed against the boss 7 to form the gas sensor mounting structure. Note that the thermal expansion coefficient (α ₁ ) of the boss 7 that is the attached portion and the thermal expansion coefficient (α ₄ , of the housing 5 and the rotating member (rotary hexagon 15) are
If the magnitude relation with α ₅ ) is α ₁ > α ₄ , α ₁ > α ₅ ,
Assuming that the temperature of the pipe 6 becomes high in this state, a gap is formed in the seal portion 3 and the tightening force of the screw portion is reduced, but the gas sensor mounting structure of the present invention has a structure of 85
Since the value of the loosening torque at 0 ° C. (1123K) and the predicted value X _{7 of the} gap calculated according to the above equation (31) are predetermined values, the tightening force of the screw portion is maintained appropriately. Therefore, the gas sensor mounting structure of the present embodiment,
Even if the gas sensor 10 is used in a high temperature condition in an installation environment where vibration is applied continuously or intermittently, the gas sensor 10 has an extremely low possibility of falling off from the attached portion (boss 7).

From the viewpoint of further reducing the possibility of falling off, the loosening torque of the rotating member at 850 ° C. (1123 K) is 15 N · m or more, and the gap calculated according to the above equation (31) is calculated. Expected value X
₇ is preferably 20 μm or less. From the same viewpoint, the loosening torque of the rotating member at 850 ° C. (1123K) is 20 N · m or more, and the predicted value X _{7 of the} gap calculated according to the above equation (31) is 15 μm.
It is more preferably m or less.

In the present invention, the loosening torque of the rotating member
Although there is no limitation on the upper limit of the
From the viewpoint of preventing the shape and biting of screws,
It may be less than the tightening torque. In addition, in the present invention
Expected value of clearance X ₁There is no limit to the lower limit of
No, the expected value of the gap X₁Is a theoretical value, so
In some cases, it may be approximately −10 μm or more.

The gas sensor mounting structure of the present invention may have a structure in which the seal portion 3 is formed via a gasket 8 as shown in FIG. In this case, the expected value X _{8 of the} gap can be calculated according to the following equation (32). At this time, the material forming the gasket is SUS43.
It is preferably at least one selected from the group consisting of 0, SUS304, SUS310, SUS316, and SUS321. These materials are materials that can exhibit good sealing performance in the seal part,
It is preferable because it has good processability.

[0066]

X ₈ (μm) = {(L ₁ × α ₁ ) − (L ₃ × α ₃ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (32) ( Where X ₈ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the thickness of the gasket (μm), and L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion of the mounted part (× 10 ⁻⁶⁾
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. )

Further, in the present invention, as the material forming the rotating member and the housing, general-purpose materials are preferably used. As a specific example, the material forming the rotating member is SUS430, SUS304, SUS31.
0, SUS316, and SUS321, and at least one selected from the group consisting of SUS430, SUS304, and SUS3.
At least one selected from the group consisting of 10, SUS316, and SUS321 is preferably adopted.

Next, a method for mounting the gas sensor of the present invention will be described. According to the present invention, a sensor element having a function of detecting a predetermined gas component, and a threaded portion for accommodating the sensor element therein and screwing the sensor element to a predetermined attachment portion formed outside thereof. And a gas sensor including a mounted portion and a housing having a sealing surface forming a sealing portion in front of the threaded portion in the direction of entry of the sensor element. The gas sensor mounting method for mounting the gas sensor on the mounted portion by screwing the housing. And 850 ° C (1
123K) so that the loosening torque is 9 N · m or more, and is calculated according to the following equation (33): 85
Provided is a method for mounting a gas sensor, which comprises screwing a housing so that an expected value X _{9 of} a gap formed between a seal surface and a mounted portion at 0 ° C. (1123K) is 31 μm or less. Hereinafter, the gas sensor mounting structure shown in FIG. 1 will be described as an example.

[0069]

X ₉ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (33) (where X ₉ is the expected value of the gap (μm), L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)).

It is the attached portion shown in FIG.
Thermal expansion coefficient of boss 7 (α ₁) And the thermal expansion coefficient of the housing 5
Number (α₂) Is greater than α₁> Α₂If this is
Assuming that the temperature of the pipe 6 becomes high in the
3, a gap is formed and the screw tightening force is reduced.
It However, in the gas sensor mounting method of the present invention, 850
Value of the loosening torque at ℃ (1123K) and the above formula
850 ° C (1123K) calculated according to (33)
Is formed between the seal surface 4 and the attached portion (boss 7) by
Expected gap X₉Housing so that and become the specified values
5 is screwed on, so that it is as high as 800 to 900 ° C.
Even under a warm condition, a suitable surface pressure is maintained in the seal part 3.
It can be a gas sensor mounting structure to be carried. Servant
Therefore, under high temperature conditions, equipment that is continuously or intermittently exposed to vibration
Even when used in a storage environment, the gas sensor
It is extremely possible that the servicer 10 will fall off the attached part (boss 7).
And a low gas sensor mounting structure can be provided.

From the viewpoint of further reducing the possibility of falling off, the loosening torque at 850 ° C. (1123K) is set to 15 N · m or more, and the clearance calculated according to the equation (33) is set. Expected value X ₉ is 20
It is preferable to screw the housing so as to have a thickness of not more than μm. From the same viewpoint, 850 ° C (1123K)
The predicted value X of the clearance calculated so that the loosening torque at 20 N · m is 20 N · m or more and according to the equation (33).
_It is more preferable to screw the housing so that ₉ is 15 μm or less.

In the present invention, the upper limit value of the loosening torque is not limited, but from the viewpoint of preventing deformation of the screw portion, biting of the screw, etc., it may be equal to or less than the torque at the time of tightening. Further, the lower limit value of the expected value X ₁ of the gap in the present invention is not limited, and the expected value X _{1 of the} gap is a theoretical value, so it may be a negative value, but it is approximately −10 μm or more. I wish I had it.

In the gas sensor mounting method of the present invention, as shown in FIG. 2, the seal portion 3 may be formed via the gasket 8. In this case, the expected value of the gap X ₁₀
Can be calculated according to the following equation (34).

[0074]

X ₁₀ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ ) − (L ₃ × α ₃ )} × 1123 (34) (However, X ₁₀ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (×
10 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10
^-6 / ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. )

Further, according to the present invention, a sensor element having a function of detecting a predetermined gas component, the sensor element is housed therein, and the attached portion and the seal portion are provided in front of the sensor element in the entering direction. A gas sensor having a housing having a sealing surface that forms a groove, a screw portion for screwing to a predetermined attachment portion formed outside the housing, and a rotating member that can rotate concentrically with the central axis of the housing Is a gas sensor mounting method for mounting a rotary member on a mounted portion by screwing the rotary member at 850 ° C.
Calculated so that the loosening torque at (1123K) is 9 Nm or more and according to the following equation (35),
A method for mounting a gas sensor, characterized in that a rotating member is screwed so that an expected value X _{11 of} a gap formed between a sealing surface and the mounted portion at 850 ° C. (1123K) is 31 μm or less. It Hereinafter, the gas sensor mounting structure shown in FIG. 3 will be described as an example.

[0076]

X ₁₁ (μm) = {(L ₁ × α ₁ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (35) (However, X ₁₁ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. Length to the lower end (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ^-6 / ° C), α ₄ is the thermal expansion coefficient of the rotating member (× 10 ^-6 / ° C), α ₅ is the housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of

In FIG. 3, a rotating member (rotary hexagon 15) that can rotate outside the housing 5 concentrically with the central axis thereof without rotating the housing 5 itself.
Is arranged and the sealing surface 4 is pressed against the boss 7 by screwing it in to form a gas sensor mounting structure. Here, the magnitude relationship between the thermal expansion coefficient (α ₁ ) of the boss 7 that is the mounted portion and the thermal expansion coefficients (α ₄ , α ₅ ) of the housing 5 and the rotating member (rotary hexagon 15) is α ₁ > α. Assuming that the temperature of the pipe 6 is high in this state when ₄ , α ₁ > α ₅ , a gap is formed in the seal portion 3 and the tightening force of the screw portion 3 is reduced.

However, in the gas sensor mounting method of the present invention, the value of the loosening torque at 850 ° C. (1123 K) and 850 ° C. (1
123K), the rotary hexagon 15 is screwed so that the expected value X _{11 of the} gap formed between the seal surface 4 and the mounted portion (boss 7) becomes a predetermined value.
The gas sensor mounting structure can maintain a suitable surface pressure in the seal portion 3 even under a high temperature condition of 900 ° C. Therefore, even when the gas sensor 10 is used under high temperature conditions in an installation environment where vibration is applied continuously or intermittently, the gas sensor mounting structure is extremely unlikely to drop off the gas sensor 10 from the mounted portion (boss 7). Can be provided.

From the viewpoint of further reducing the possibility of falling off, the loosening torque at 850 ° C. (1123K) is 15 N · m or more, and the clearance calculated according to the above equation (35) is set. Expected value X ₁₁ is 20
It is preferable to screw the rotating member so that the thickness becomes equal to or less than μm. Further, from the same viewpoint, the expected value X of the clearance calculated so that the loosening torque at 850 ° C. (1123 K) becomes 20 N · m or more and according to the equation (35).
_It is more preferable to screw the rotating member so that ₁₁ is 15 μm or less.

In the present invention, the upper limit value of the loosening torque is not limited, but from the viewpoint of preventing the deformation of the screw portion, the biting of the screw, etc., it may be equal to or less than the torque at the time of tightening. Further, the lower limit value of the expected value X ₁ of the gap in the present invention is not limited, and the expected value X _{1 of the} gap is a theoretical value, so it may be a negative value, but it is approximately −10 μm or more. I wish I had it.

In the gas sensor mounting method of the present invention, as shown in FIG. 4, the seal portion 3 may be formed via the gasket 8. In this case, the expected value of the gap X ₁₂
Can be calculated according to the following equation (36).

[0082]

X ₁₂ (μm) = {(L ₁ × α ₁ ) − (L ₃ × α ₃ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (36) ( Where X ₁₂ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the gasket thickness (μm), and L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion (× 10
^-6 / ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. )

In addition, in the gas sensor mounting method of the present invention, general-purpose materials are used as the materials for forming the gasket, the rotating member, and the housing.
Specifically, the material of the gasket is SUS
430, SUS304, SUS310, SUS316,
And at least one selected from the group consisting of SUS321 is used as the material for the rotating member.
0, SUS304, SUS310, SUS316, and SUS321, and at least one selected from the group consisting of SUS4.
30, SUS430, SUS304, SUS310, S
At least one selected from the group consisting of US316 and SUS321 can be preferably used.

[0084]

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to these examples.

(Relationship between Gas Sensor Dropout and Loosening Torque and Expected Value of Gap) Each constituent member made of the materials shown in Table 1 was prepared and the rotary hexagon was bossed with a tightening torque of 30 N · m or more under room temperature conditions. It was screwed on to prepare a gas sensor mounting structure having the structure shown in FIG. 3 (Sample Nos. 1 to 1).
3). The length (L ₁ : mm) from the sealing surface to the upper end of the boss (attached portion) is as shown in Table 1. The obtained gas sensor mounting structure is exposed to a high temperature condition of 850 ° C.,
The loosening torque (Nm) of the rotary hexagon at that time was measured. In addition, the coefficient of thermal expansion of each material used (×
The expected value (μm) of the gap formed between the seal surface and the boss was calculated from 10 ⁻⁶ / ° C.) and the length (mm) of each place (L ₁ , L _{3 to} L ₅ ). A graph in which the loosening torque (N · m) is plotted against the obtained numerical values is shown in FIG. Further, a vibration test was performed on the produced gas sensor mounting structure to confirm whether or not the gas sensor was dropped. The results are shown in Fig. 5.

[0086]

[Table 1]

From the results shown in FIG. 5, 850 ° C. (112
The loosening torque of the rotary hexagon at 3K) is 9N
It has been found that the gas sensor does not fall off from the boss that is the attached portion when the gap is m or more and the expected value of the gap is 31 μm or less. In other words, by properly selecting the material and dimensions of the rotary hexagon, gasket, and housing for the material and dimensions of the boss, and by appropriately controlling the tightening force (loosening torque) of the rotary hexagon, the gas sensor can be prevented from falling It turns out that it can be prevented in advance.

[Measurement of Loosening Torque]: The loosening torque of the rotary hexagon (rotating member) of the produced gas sensor mounting structure was measured according to the method described below. First,
A gas sensor is attached to the pipe to form a gas sensor attachment structure, and then a gas of 850 ° C. is flown inside the pipe,
The gas sensor mounting structure is heated. After exposing this state for 2 hours, the value of the loosening torque measured with the torque gauge is
The value was the loosening torque value (N · m) at 850 ° C.

[Vibration test]: A vibration test was performed on the produced gas sensor mounting structure using the test apparatus and conditions shown in Table 2.

[0090]

[Table 2]

(Examples 1 to 4 and Comparative Examples 1 and 2) Each constituent member made of the material shown in Table 3 was prepared and subjected to 60
The rotary hexagon was screwed onto the boss with a tightening torque of N · m or 40 N · m to fabricate a gas sensor mounting structure having the structure shown in FIG. The obtained gas sensor mounting structure was exposed to a high temperature condition of 850 ° C., and the loosening torque (N · m) of the rotary hexagon at that time was measured. In addition, from the coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of the material of each member used and the length (mm) of each location (L ₁ , L _{3 to} L ₅ ) between the sealing surface and the boss. The expected value (μm) of the formed gap was calculated. Table 3 shows the loosening torque value (N · m) at 850 ° C. and the expected gap value (μm). Further, FIG. 6 shows a graph in which the loosening torque (N · m) at 850 ° C. is plotted against the predicted value of the gap.

[0092]

[Table 3]

Further, a vibration test was performed on the produced gas sensor mounting structure to confirm whether or not the gas sensor was dropped. As a result, it was found that the gas sensor did not fall off in Examples 1 to 4, but the gas sensor fell out in Comparative Examples 1 and 2 (Table 3). Therefore, as shown in FIG. 6, when the loosening torque of the rotary hexagon at 850 ° C. (1123K) is 9 N · m or more and the expected value of the gap is 31 μm or less, the gas sensor is the attached portion. I was able to confirm that I would not drop from the boss.

[0094]

As described above, in the gas sensor of the present invention, the value of the loosening torque at the predetermined temperature when the housing or the rotating member, which is the constituent member, is screwed to the mounted portion, and the sealing surface Since the expected value of the gap formed between the part to be attached and the part to be attached is a predetermined value, the tightening force of the screw is less likely to decrease even when installed and used under high temperature conditions, and vibration is further applied. In this case also, the effect that it is difficult to fall off the attached portion is exhibited. Further, in the gas sensor mounting structure of the present invention, the value of the loosening torque of the housing or the rotating member at a predetermined temperature and the expected value of the gap formed between the seal surface and the mounted portion are predetermined values. Even when it is installed and used under high temperature conditions, the tightening force of the screw does not easily decrease, and even when vibration is applied, it does not easily come off from the attached part.

Further, according to the gas sensor mounting method of the present invention, the loosening torque at a predetermined temperature and the expected value of the gap formed between the seal surface and the mounted portion become a predetermined value. Since the housing or the rotating member is screwed, it is possible to fabricate a gas sensor mounting structure in which the gas sensor is extremely unlikely to fall off even when used in an installation environment where vibration is applied under high temperature conditions.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing an embodiment of a gas sensor mounting structure of the present invention.

FIG. 2 is a partial cross-sectional view showing another embodiment of the gas sensor mounting structure of the present invention.

FIG. 3 is a partial cross-sectional view showing another embodiment of the gas sensor mounting structure of the present invention.

FIG. 4 is a partial cross-sectional view showing another embodiment of the gas sensor mounting structure of the present invention.

FIG. 5 is a graph showing a relationship between a gas sensor dropout, a loosening torque (N · m), and an expected value (μm) of a gap.

FIG. 6 is a graph in which the loosening torque (N · m) at 850 ° C. is plotted against the predicted value (μm) of the gap for each gas sensor mounting structure manufactured in the example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Sensor element, 2 ... Screw part, 3 ... Seal part, 4 ... Sealing surface, 5 ... Housing, 6 ... Piping, 7 ... Boss, 8 ... Gasket, 10 ... Gas sensor, 15 ... Rotating hexagon.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Lee             2-56, Sudacho, Mizuho-ku, Nagoya-shi, Aichi             Inside Hon insulator Co., Ltd. F term (reference) 2G004 BC09 BG05 BM04                 3J040 BA03 EA17 HA06 HA16

Claims (20)

[Claims] 1. A sensor element having a function of detecting a predetermined gas component, and a threaded portion for accommodating the sensor element therein and screwed to a predetermined attachment portion formed outside thereof. And a housing having a sealing surface that forms a seal portion with the attached portion in front of the threaded portion in the approach direction of the sensor element, wherein the housing is screwed to the attached portion. 8 when worn
The loosening torque at 50 ° C (1123K) is 9 N · m or more, and the loosening torque is calculated according to the following equation (1).
The expected value X _{1 of the} gap formed between the sealing surface and the attached portion in K) is 31 μm or less. ## EQU1 ## X ₁ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (1) (where X ₁ is the expected value of the gap (μm) and L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)). 2. The gas sensor according to claim 1, wherein a gasket is provided on the sealing surface, and the expected value X _{2 of the} gap is calculated according to the following formula (2). ## EQU00002 ## X ₂ (μm) = {(L ₁ × α ₁ )-(L ₂ × α ₂ )-(L ₃ × α ₃ )} × 1123 (2) (where X ₂ is a gap prediction Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (× 1
0 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10 ^-6
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. ) 3. The material forming the gasket is SUS
430, SUS304, SUS310, SUS316,
The gas sensor according to claim 2, wherein the gas sensor is at least one selected from the group consisting of and SUS321. 4. A sensor element having a function of detecting a predetermined gas component, and a seal for accommodating the sensor element therein and for forming a seal portion with the attached portion in front of an entering direction of the sensor element. A gas sensor comprising: a housing having a surface; and a rotating member that has a threaded portion to be screwed to a predetermined mounting portion formed on the outside thereof and that is rotatable concentrically with the central axis of the housing. In the case where the gas sensor is attached to the attached portion by screwing the rotating member to the attached portion,
The loosening torque of the rotating member at 850 ° C. (1123 K) is 9 N · m or more, and the loosening torque is calculated according to the following formula (3).
The expected value X _{3 of the} gap formed between the sealing surface and the attached portion in K) is 31 μm or less. ## EQU00003 ## X ₃ (μm) = {(L ₁ × α ₁ )-(L ₄ × α ₄ )-(L ₅ × α ₅ )} × 1123 (3) (where X ₃ is a gap prediction Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. to bottom length (μm), α ₁ is the thermal expansion coefficient of the attachment portion ^{(× 10 - 6 / ℃)} , α 4 are the thermal expansion coefficient of the rotating member ^{(× 10 -6 / ℃),} α 5 housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of 5. The gas sensor according to claim 4, wherein a gasket is provided on the sealing surface, and the expected value X _{4 of the} gap is calculated according to the following equation (4). X ₄ (μm) = {(L ₁ × α ₁ ) − (L ₃ × α ₃ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (4) ( Where X ₄ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the thickness of the gasket (μm), L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion of the mounted part (× 10 ⁻⁶⁾
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. ) 6. The material forming the gasket is SUS
430, SUS304, SUS310, SUS316,
The gas sensor according to claim 5, wherein the gas sensor is at least one selected from the group consisting of and SUS321. 7. The material forming the rotating member is SUS4.
The gas sensor according to any one of claims 4 to 6, which is at least one selected from the group consisting of 30, SUS304, SUS310, SUS316, and SUS321. 8. The material forming the housing is SUS
430, SUS304, SUS310, SUS316,
And at least one selected from the group consisting of SUS321 and the gas sensor according to claim 1. 9. A sensor element having a function of detecting a predetermined gas component, and a threaded portion for accommodating the sensor element therein and screwed to a predetermined attachment portion formed outside thereof. A gas sensor having the attached portion and a housing having a sealing surface forming a seal portion in front of the threaded portion in the approach direction of the sensor element, and the housing is screwed to the attached portion. In the gas sensor mounting structure mounted by the above, the loosening torque of the housing at 850 ° C. (1123K) is 9 N · m or more, and 850 ° C. (1123) calculated according to the following formula (5).
In K), the expected value X _{5 of the} gap formed between the sealing surface and the mounted portion is 31 μm or less, and the gas sensor mounting structure. X ₅ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (5) (where X ₅ is the expected value of the gap (μm), L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)). 10. The gas sensor mounting structure according to claim 9, wherein the seal portion is formed via a gasket, and the expected value X _{6 of the} gap is calculated according to the following equation (6). ## EQU6 ## X ₆ (μm) = {(L ₁ × α ₁ )-(L ₂ × α ₂ )-(L ₃ × α ₃ )} × 1123 (6) (where, X ₆ is a predicted gap) Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (× 1
0 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10 ^-6
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. ) 11. The material forming the gasket is SU.
S430, SUS304, SUS310, SUS31
The gas sensor mounting structure according to claim 10, which is at least one selected from the group consisting of 6 and SUS321. 12. A sensor element having a function of detecting a predetermined gas component, and a seal for accommodating the sensor element therein and forming a seal portion with the attached portion in front of an entering direction of the sensor element. A gas sensor including a housing having a surface and a rotating member that has a threaded portion to be screwed to a predetermined mounted portion formed on the outside thereof and that is rotatable concentrically with the central axis of the housing, A gas sensor mounting structure mounted on the mounted portion by screwing the rotating member, wherein the loosening torque of the rotating member at 850 ° C. (1123K) is 9 N · m or more, and Calculated according to (7), 850 ° C (1123
In K), the expected value X _{7 of the} gap formed between the sealing surface and the attached portion is 31 μm or less, and the gas sensor mounting structure. ## EQU00007 ## X ₇ (μm) = {(L ₁ × α ₁ )-(L ₄ × α ₄ )-(L ₅ × α ₅ )} × 1123 (7) (However, X ₇ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. to bottom length (μm), α ₁ is the thermal expansion coefficient of the attachment portion ^{(× 10 - 6 / ℃)} , α 4 are the thermal expansion coefficient of the rotating member ^{(× 10 -6 / ℃),} α 5 housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of 13. The gas sensor mounting structure according to claim 12, wherein the seal portion is formed via a gasket, and the expected value X _{8 of the} gap is calculated according to the following formula (8). X ₈ (μm) = {(L ₁ × α ₁ ) − (L ₃ × α ₃ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (8) ( Where X ₈ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the thickness of the gasket (μm), and L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion of the mounted part (× 10 ⁻⁶⁾
/ ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. ) 14. The material forming the gasket is SU.
S430, SUS304, SUS310, SUS31
The gas sensor mounting structure according to claim 13, wherein the gas sensor mounting structure is at least one selected from the group consisting of 6 and SUS321. 15. The material forming the rotating member is SUS
430, SUS304, SUS310, SUS316,
And at least one selected from the group consisting of SUS321 and the gas sensor mounting structure according to any one of claims 12 to 14. 16. The material forming the housing is SU.
S430, SUS304, SUS310, SUS31
6. The gas sensor mounting structure according to claim 9, wherein the gas sensor mounting structure is at least one selected from the group consisting of 6 and SUS321. 17. A sensor element having a function of detecting a predetermined gas component, and a threaded portion for accommodating the sensor element therein and screwing the sensor element to a predetermined attachment portion formed outside thereof. And a housing having a sealing surface that forms a seal portion with the attached portion in front of the threaded portion in the approach direction of the sensor element, the attached portion by screwing the housing. Is a method of mounting a gas sensor that is mounted on, and the loosening torque at 850 ° C (1123K) is 9 N · m.
850 ° C. (1123) calculated as described above and according to the following equation (9).
In K), the housing is screwed so that the expected value X _{9 of the} gap formed between the sealing surface and the attached portion is 31 μm or less. X ₉ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ )} × 1123 (9) (where X ₉ is the expected value of the gap (μm), L ₁ is The length from the sealing surface to the upper end of the mounted part (μm), L ₂ is the length from the sealing surface to the upper end of the threaded part (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ⁻⁶ / ° C.), alpha ₂ is the thermal expansion coefficient of the housing (× 10 ^- shows the ⁶ / ℃)). 18. The housing according to claim 17, wherein the seal portion is formed through a gasket, and the housing is screwed so that an expected value X _{10 of the} gap calculated according to the following formula (10) is 31 μm or less. How to install the gas sensor described. X ₁₀ (μm) = {(L ₁ × α ₁ ) − (L ₂ × α ₂ ) − (L ₃ × α ₃ )} × 1123 (10) (However, X ₁₀ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₂ is the length from the sealing surface to the top of the threaded part (μm), L ₃ is the gasket thickness ( μm), α ₁ is the coefficient of thermal expansion of the attached part (×
10 ^-6 / ° C), α ₂ is the coefficient of thermal expansion of the housing (× 10
^-6 / ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C) is shown. ) 19. A sensor element having a function of detecting a predetermined gas component, and a seal for accommodating the sensor element therein and for forming a seal portion with the attached portion in front of an entering direction of the sensor element. A gas sensor having a housing having a surface and a rotating member that is concentric with the central axis of the housing and that has a screw portion for screwing to a predetermined mounted portion formed on the outside of the housing. A method for mounting a gas sensor, which is mounted on the mounted portion by screwing a member, wherein a loosening torque at 850 ° C. (1123K) is 9 N · m.
850 ° C. (112 ° C.) calculated as described above and according to the following equation (11).
3K), the rotating member is screwed so that the expected value X _{11 of the} gap formed between the sealing surface and the attached portion is 31 μm or less. X ₁₁ (μm) = {(L ₁ × α ₁ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (11) (However, X ₁₁ is a predicted gap. Value (μm), L ₁ is the length from the sealing surface to the upper end of the mounted part (μm), L ₄ is the length from the lower end to the upper end of the threaded part (μm), L ₅ is the length from the sealing surface to the threaded part. Length to the lower end (μm), α ₁ is the thermal expansion coefficient of the mounted part (× 10 ^-6 / ° C), α ₄ is the thermal expansion coefficient of the rotating member (× 10 ^-6 / ° C), α ₅ is the housing The coefficient of thermal expansion (× 10 ⁻⁶ / ° C.) of 20. The housing is screwed so that the seal portion is formed via a gasket and the predicted value X _{12 of the} gap calculated according to the following formula (12) is 31 μm or less. How to install the gas sensor described. X ₁₂ (μm) = {(L ₁ × α ₁ ) − (L ₃ × α ₃ ) − (L ₄ × α ₄ ) − (L ₅ × α ₅ )} × 1123 (12) ( Where X ₁₂ is the expected value of the gap (μm), L ₁ is the length from the sealing surface to the top of the mounted part (μm), L ₃ is the gasket thickness (μm), and L ₄ is the top of the threaded part. To the lower end (μm), L ₅ is the length from the sealing surface to the lower end of the threaded portion (μm), α ₁ is the coefficient of thermal expansion (× 10
^-6 / ° C), α ₃ is the coefficient of thermal expansion of the gasket (× 10 ^-6 /
° C), α ₄ is the coefficient of thermal expansion of the rotating member (× 10 ^-6 / ° C),
α ₅ represents the thermal expansion coefficient (× 10 ⁻⁶ / ° C.) of the housing. )